1. Field of the Invention
The present invention is directed to the field of automotive lamp and socket assemblies and more specifically to the area of an improved retaining mechanism to secure a generally parallelopiped-shaped lamp base within a socket.
2. Description of the Prior Art
A prior art wedge base lamp and socket is disclosed in commonly assigned U.S. Pat. No. 4,647,132. The patent describes a retaining mechanism for a lamp socket wherein a single wire spring element is mounted external to the lamp socket, but protrudes into the lamp socket opening. In this manner, the portions of the spring element that protrude into the socket opening provide both insertion interference to the forward ends of ramped projections extending from either end of the lamp base and frictional retention against the rearward ends of the ramped projections when the wedge base element is fully inserted.
The spring used in the latest embodiment of the '132 device in production is shown in FIG. 1 hereof as a generally "C" or "U" shaped element 300 having a pair of legs 310 and 312 integrally joined together at respective corners 306 and 308 by a base member 304. The base member 304 has a slight offset bend at point 302 that makes leg 312 slightly longer than leg 310. The remote end 311 of leg 312 has an inward bend so that it may be secured to a portion of the socket during installation and prevent subsequent slipping of the spring from its installed position on the socket. The remote end point 309 of leg 310 contains an outward bend to provide a cam surface. The cam surface provided by the bend in the remote end 309 is used during installation of the spring on the socket by providing a sliding surface once leg end 311 has been secured in place.
From time to time it has been found that the prior art spring shown in FIG. 1 when installed in the socket of the '132 patent is ineffective in retaining the lamp base in the socket. It has been found that the spring sometimes becomes deformed during installation due to severe bending stresses present at corners 306 and 308. Because the spring has to be stretched outwardly to be placed on the sockets, instances have occurred where springs have become permanently deformed; and, therefore, have less holding biased ability for holding the lamp base in place.